A standard bracket assembly for mounting a tank-type fire extinguisher thereon normally comprises a clamping mechanism for releasing the fire extinguisher should the need arise. Bracket assemblies and clamping mechanisms of this type may exhibit the tendency to permit the fire extinguisher to become disloged inadvertently from the bracket assembly during operation of a vehicle on which it is mounted. In addition, such bracket assemblies do not provide means for ejecting fire extinguishers therefrom for ready use by the operator of the vehicle.